The Expression of GLAST and GLT1 in a Transient Cerebral Ischemia Mongolian Gerbil Model

Abstract

Yanling Shen,1,2 Huiling Lu,1 Runnan Xu,1 Haibo Tian,1 Xuewei Xia,1 Fiona H Zhou,3 Liping Wang,3 Jianghui Dong,4 Liyuan Sun1 1Department of Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Guilin Medical University, Guilin, Guangxi 541004, People’s Republic of China; 2Department of Pathology, Affiliated Chenggong Hospital, Xiamen University, Xiamen, Fujian 361000, People’s Republic of China; 3School of Pharmacy and Medical Sciences, University of South Australia, Cancer Research Institute, University of South Australia, Adelaide, SA 5001, Australia; 4College of Pharmacy, Guilin Medical University, Guilin, Guangxi 541199, People’s Republic of ChinaCorrespondence: Jianghui DongCollege of Pharmacy, Guilin Medical University, Guangxi, Guilin 541199, People’s Republic of ChinaTel [phone]Fax [phone]Email [email protected] SunDepartment of Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Guilin Medical University, Guilin 541004, Guangxi, People’s Republic of ChinaTel [phone]Fax [phone]Email [email protected]: Excitatory amino acid transporters (EAATs) have an indispensable function in the reuptake of extracellular glutamate. To investigate the relationship and the expression of neuronal and astrocytic markers after brain ischemia, the temporal profile of glial EAATs in both peripheral and core regions of the cortex was examined.Methods: Transient common carotid artery occlusion was used to induce unilateral transient forebrain ischemia of Mongolian gerbils, and post-ischemic brains (6 h to 2 w) were collected and prepared for immunohistochemical and Western blotting analysis of glutamine synthetase (GS), GLT-1, GLAST, S100β, and NeuN, and for Alizarin red staining of calcium deposits.Results: The expression of GLAST and GLT-1 were significantly escalated at 6 h both in the core and periphery regions, while reduced from 12 h to 2 w in the core region post-ischemia. GS-positive cells increased at 6 h both in the core and periphery regions, while the density of Alizarin red-positive cells increased and peaked at 12 h in the ischemic cortex. The density of S100β-positive cells decreased in the ischemic core and increased in the periphery region. Immunofluorescence staining showed that S100β and TUNEL double-positive cells increased at 12 h in the core region.Conclusion: The results of GLT-1 and GLAST expression in the cortex indicate that their up-regulation was time-dependent and occurred in the acute post-ischemia period, whereas their down-regulation was region-dependent and it is involved in the pathological progress of nerve cell and glial cell death, and has a series of cascade reactions.Keywords: glutamate transporter, forebrain ischemia, astrocyte, neuronal death, Mongolian gerbil  

Keywords

• glutamate transporter
• forebrain ischemia
• astrocyte
• neuronal death
• mongolian gerbil